Side dump loader



Feb. 22, 1966 E. a. WAGNER SIDE DUMP LOADER 2 Sheets-Sheet 1 Filed June 12.54 1964 HWS .Ausl

INVENTOR EDDIE B. WAGNER Attorney Feb. 22, 1966 E. B. WAGNER 3,236,401

SIDE DUMP LOADER Filed June 25, 1964 2 Sheets-Sheet 2 I l I l/T I I I I 1 I VH 3Q INVENTOR.

EDD| E B. WAGNER United States Patent O 3,236,401 SIDE DUMP LOADER Eddie B. Wagner, Portland, Oreg., assignor to Wagner Manufacturing, Inc., Portland, Oreg., a corporation of Oregon Filed June 25, 1964, Ser. No. 377,906 14 Claims. (Cl. 214-132) This invention relates to loaders and has particular reference to improvements allowing a loader to dump to either side.

This application is a continuation-in-part of my prior copending application on Side Dump Loader, Serial No. 299,652, liled August 2, 1963.

A loader is a self-propelled vehicle having a scoop-type bucket mounted on a forwardly extending boom. The bucket is lled by driving the vehicle forward with the bucket tilted forward and sliding on the ground so as to scoop up loose material on the ground such as earth, rocks, sand or ore. Then the bucket is tilted back to retain the scooped up material and the boom is raised. With the bucket thus elevated, the vehicle may be maneuvered to position the bucket over some means of conveyance such as a truck or conveyor belt. The load is discharged either by tipping the bucket forward or by opening the bottom.

The utility of such loaders has heretofore been limited by the inability of the boom to swing from side to side whereby the load could only be dumped straight forward. In some working areas, as for example in a mine or tunnel, there is insufficient space to turn the vehicle in order to reach a conveyance close by. This has necessitated driving the loader in reverse for great distances, delaying excavation work and idling work crews and machines while awaiting return of the loader.

Previous attempts have been made to dump to one side but such machines have other objectionable limitations, For example, loaders have been developed which will raise one end of the bucket in order to discharge to one side of the vehicle out of the other end of the bucket. In such case the loader is usually limited to either right or left side dumping and the operator cannot dump on the opposite side when he might wish to do so. Even so, the end-tilted bucket will not cast its load appreciably beyond the side of the machine, which may be necessary in some cases. A more critical objection is that in mine or tunnel work there may not be sufficient overhead clearance to permit one end of a large bucket to be raised sufliciently high for side dumping.

The general object of the present invention is, therefore, to provide a side dump loader which overcomes the disadvantages and shortcomings of prior machines as pointed out above.

More specifically, the object of the invention is to provide a side dump loader adapted to the lateral and overhead space limitations of a mine or tunnel. Other objects are to provide a novel and improved laterally swinging boom, to provide means for centering the boom in straight forward position until the boom is elevated sufticiently to swing over the front wheels of the vehicle, and to provide novel hydraulic levelling and dumping means for the bucket in a loader.

In the present loader the boom has a lower section which pivots up and down but does not swing. An upper boom section is arranged to swing about a pivotal axis on the lower section, which axis becomes vertical when the lower section is raised to dumping position, This permits the bucket to turn parallel with the vehicle in overhanging position at a distance out from either the left or right side of the vehicle. The upper boom section is locked in straight forward position when the boom is lowered.

3,236,401 Patented Feb. 22, 1966 ICC Additional objects and advantages will become apparent and the invention will be better understood from the following detailed description of a preferred embodiment illustrated in the accompanying drawings. Various changes may be made, however, in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

In the drawings:

FIGURE 1 is a side elevation view of a loader embodying the principles of the invention and showing the boom in raised position in broken lines;

FIGURE 2 is a top plan view of the front portion of the loader in FIGURE 1;

FIGURE 3 is an enlarged sectional view taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a top plan view similar to FIGURE 2 but showing the boom turned to side dumping position;

FIGURE 5 is a diagram of the hydraulic system for swinging the boom; and

FIGURE 6 is a diagram of the hydraulic system for levelling and dumping the bucket.

The loader vehicle comprises a front body unit or bogie A, a rear body unit or bogie B and an intermediate frame C. The front body unit A has a single axle 10 rigid with the frame of the unit carrying a pair of front wheels 11. The rear body unit B has a single axle rigid with the frame of the unit carrying a pair of rear wheels 12. This unit has an engine 13 arranged to drive all four wheels. The operator occupies a cab 14 for operating the bucket and driving the vehicle backward and forward.

The intermediate frame C has upper and lower rearwardly extending tongues 16 and 17 pivotally connected by vertical pins 18 with upper and lower ears 19 and 20 on the rear body unit. These pins define a pivotal axis of articulation between the front and rear body units for steering. Steering is accomplished by a pair of horizontal obliquely disposed double acting cylinders 21 which are pivotally connected to the front end of unit B. Piston rods 22 in these cylinders are pivotally connected at their divergent outer ends with opposite sides of the frame unit C. When one piston rod is extended and the other retracted, the two body units and their axles are forced into angular relationship causing the vehicle to turn.

In order to provide tiexibility for travel over uneven ground surfaces, there is a swivel connection on the longitudinal axis interconnecting the units A and C. This swivel connection comprises a cylindrical trunnion 23 extending forward from frame C and mounted for rotative oscillation in a cylindrical bearing 24 in body unit A. Thus, the intermediate frame C turns with front body unit A about the vertical axis of pins 18 in steering and oscillates with the rear body unit B about the longitudinal axis of trunnion 23 in negotiating uneven ground. The drive shaft 25 for the front wheels extends through the center of trunnion 23 with suitable universal joints to a transmission associated with the engine in unit B.

The loader bucket 30 is carried -by -a boom having a lower boom section 31 and an upper boom section or assembly 32. Lower boom section 31 hinges vertically on a boom heel pin 33 on opposite sides of the frame of body unit A. The boom may be raised and lowered by a pair of double acting cylinders 35 having pivotal connection 36 at the lower ends with brackets 37 on the opposite sides of the frame. Piston rods 38 in the upper ends of these cylinders are pivotally connected at 39 with the lower boom section.

The upper end of lower boom section 31 has ears 44 iournaled on a pair of aligned pivot pins 45 which are disposed at such :an angle that when the lower boom section is fully raised the pivot axis will be verti-cal as shown in broken lines in FIGURE l. Upper boom section 32 has ears 46 connected with the pins 45 allowing the upper boom section to turn at right angles to the lower boom section for side dumping on either side of the loader when the boom is raised, as shown in FIGURE 4. Because of the vertical position `of pins 4S when the boom is raised, the fully loaded bucket will swing relatively easily in a horizontal plane to its side positions.

A pair of bucket carrying arms 49 are rigidly mounted lon opposite sides of the outer end of the upper boom sec- -tion 32. The forward ends of these arms are pivotally connected with the underside of the bucket at 51 while the rear ends are pivotally connected at 52 with a pair of movable arms 53 on oposite sides of the upper boom section. The upper ends of these arms are piv-otally connected `at 54 with the rear ends of links 55. The forward ends of links 55 are pivotally connected at 57 with the rear side of the bucket. Intermediate the ends of arms 53 are pivotal connections 58 for the piston rods 59 of double acting levelling and dumping cylinders 60. The forward ends of these cylinders are pivotally connected at 61 to the arms 49.

A bucket levelling master cylinder 65 has its lower end pivotally connected at 66 on a bracket 67 on the frame of front body unit A. A piston rod 68 extending from the upper end of this cylinder is pivotally connected at 69 to the lower boom section 31. There is only one of these cylinders. The function of this cylinder will be presently des-cribed in connection with FIGURE 6.

The mechanism for swinging the upper boom section is shown essentially in FIGURES 2 and 4. This mechanism comprises a right swing cylinder 75 and a left swing cylinder 76 and includes `a novel linkage and locking mechanism. The :right swing cylinder 75 is on the left side of the bo-om for swinging the upper boom section 32 to the right on pivot 45 and the left swing cylinder 76 is on the right side of the boom for swinging the upper boom section to the left. The rear ends of these cylinders are pivotally connected with pins 74 -on the lower boom section 31.

Right swing cylinder 75 has a piston rod 77 pivotally connected at 78 with the rear end of a right swing lever 79. Left swing cylinder 76 Ihas a piston rod 80 pivotally connected at 81 with the rear end of a left swing lever 82. Both of these levers are pivotally mounted intermediate their ends for free swinging movements on the upper pivot pin 45 of the boom. The forward end of lever 79 is equipped with a perpendicular pin 83 'and the forward end of lever 82 is equipped with a perpendicular pin 84. These levers cross each other at an angle in a scissors conguration. A boom swing drive link 85 is pivotally mounted at its center on a pin 86 on the upper boom section 32. This link has a rearwardly facing notch 87 in each end, which notches are engageable selectively with the lever pins 83 and 84. For `this purpose, the link 85 may be rocked back and forth by `a double acting cylinder and piston r-od unit 90 `as shown in FIGURE 5.

Provision is made 4for locking theupper boom section 32 in straight forward position so that it will pass between front wheels 11 and not strike one of these wheels when the lboom is raised and lowered. For this purpose, the upper boom section '32 has an integral swing lock arm 32a extending rearwardly behind the pivot 45 and `arranged to overlie a flat top plate 88 on the lower boom section 31, Ias shown in FIGURES 1, 2 and 3. Retractable swing lock bars 95 and 96 are positioned on opposite sides of arm 32a to prevent swinging of the arm .and upper boom section 32. As shown in FIGURE 3,

,the lock bars are actuated by piston rods 97 in double acting cylinders 98 and 99. In this way the lock bars may be 4raised or retracted individually as will be presently explained in connection with FIGURE 5. Bar 95 is on the left side of arm 32a to prevent upper boom section 32 from swinging to the right and bar 96 is on the right side of arm 32a to prevent the upper boom section from swinging to the left.

In FIGURE 2 the boom is raised and the parts `are shown in position for swinging the upper boom section and bucket to the left, which movement requires the rear end of lock arm 32a to swing to the right. Lock 'bar 96 is retracted and drive link 85 is engaged with pin 84 and disengaged from pin 83. In leftward swinging movement of the bucket the cylinder 75 remains inactive. Leftward swing is produced by Iapplying fluid pressure to the rear end of cylinder 76, causing piston rod 30 to be extended forward. This swings lever 82 counterclockwise and with it the uper boom section 32. The bucket is returned vto straight forward position by `applying fluid pressure to the forward end of cylinder 76 to retract piston rod 3@ and swing lever 82 clockwise. Stops 100 on opposite -sides of lower boom section 31 limit the swing of upper boom section 32 to 90 left and right.

FIGURE 3 shows lock bar 95 retracted for swinging the bucket to the right and FIGURE 4 shows the boom raised Iand the bucket swung to the right for dumping into a truck T alongside the loader vehicle. F-or this movement the drive link 5 is rocked clockwise so that one of its notches 87 will engage the pin 83 causing the notch in the other end to disengage pin 84. During a right swing, cylinder '76 remains inactive. When fluid pressure is applied to the rear end of cylinder 75, its pistori rod 77 is extended causing lever 79 to rotate cloclwise and swing the upper boom section in the same direction. During this movement, lock arm 32a passes over the retracted lock bar 95.

The bucket is returned to straight forward position by applying fluid pressure to the forward end of cylinder 7S to retract its piston rod. In this return movement the raised lock bar 96 serves to stop the arm 32a and then lthe other lock bar is raised to lock the parts in straight forward position before the bucket is lowered to the ground for a new load. Since in the present form of construction the upper end of the boom must pass between the front wheels 11, the upper boom section must remain straight forward until the boom has been raised sufficiently tvo clear the wheels. Unloading as shown in FIGURE 4 is accomplished with the boom in elevated position whereby the boom does not need to be lowered when it is swung to the side. Also, Ias previously pointed out, it 1s desired t-o maintain pivot axis 45 in vertical position during any swinging movement so that the bucket will swing in `a horizontal plane.

Stabilizing cylinders on opposite sides of the vehicle lock front body unit A to rear body unit B through the intermediate frame C as described in said application 299,652 to prevent overturning. The present boom and bucket arrangement may be used on a vehicle having an oscillating rear axle instead of the swivel trunnion 23 as also described in said appli-cation 299,652.

The right and left swinging movements of upper boom section 32 are controlled by the hydraulic system shown 1n FIGURE 5. This system is energized by a source of fluid pressure such as the pump 120, the hydraulic uid displaced by the pistons of the various cylinders returning to the tank 121. The cylinders 75, 76, 96, 9S and 99 are connected by hydraulic conduits with a plurality of control valves. Valves 122 and 123 are manually operated valves and 126 is a relay valve operated by a piston in cylinder 127.

The source of pressure is connected by hydraulic pressure line 130 to one side of both valves 122 and 123. From the same side of these valves a discharge or relief line 131 leads to the tank or sump 121. The opposite side of valve 122 is connected to a pair of hydraulic lines 132 and 133 leading to opposite ends of double acting cylinder 127 for actuating the relay valve 126. Lines 132 and 133 also communicate with opposite ends of drive link cylinder 90. A pair of lines 134 and 135 connect the opposite side of valve 123 with one side of valve 126. In one position of valve 126 the lines 134 and 135 are connected to a pair of lines 136 and 137 while in another position of the valve they are connected with a pair of lines 138 and 139.

Line 137 yis connected to the forward end of boom swing cylinder 75, check valve 124 and pressure relief valve 125. Line 136 connects with the upper end of lock bar cylinder 98 and the rear end of cylinder 75. Similarly, line 138 connects with the rear end of boom swing cylinder 76 and the upper end of lock bar cylinder 99 while line 139 connects with the forward end of cylinder 76, check valve 140 and pressure relief valve 141. The lower end of cylinder 98 is connected through line 142 to check valve 124 and relief valve 125 and the lower end of cylinder 99 is connected through line 143 with check valve 140 and relief valve 141. Pressure relief valves 125 and 141 are each held closed by a spring 144 which does not yield until practically the full available pressure of source 120 is applied.

In explaining the operation of the hydraulic system in FIGURE 5, it is pointed out that the upper boom section 32 is normally locked in straight forward position by arm 32a between the raised lock bars 95 and 96 and discharge lines 130 and 131 are both `closed at the Valves 122 and 123 which are in neutral or olf positions as shown, shutting olf the pressure and discharge connections 130 and 131 from all the other lines, cylinders and valves. Thus, the pistons in the various cylinders remain hydraulically locked in the positions to which they were last actuated. In the case of cylinders 75 and 76, both pistons Will always be fully retracted when the upper boom section is centered in straight forward position. In the case of cylinders 98 and 99, both pistons will be at the top ends of the cylinders when the boom is centered. The positions of the pistons in cylinders 90 and 127 depend upon the previous direction of boom swing.

In order to swing the upper boom section to the right, the valve 122 is first shifted to the right connecting pressure line 130 with line 132 and discharge line 131 with line 133. Pressure in line 132 operates cylinder 127 to shift valve 126 to the left as shown and operates cylinder 90 to swing drive link 85 clockwise as shown, to engage pin 83 as shown in FIGURE 4. These functions are merely preparatory to swinging the boom and once they have been accomplished, the valve 122 may, if desired, be allowed to return to its neutral or off position. This effects a hydraulic lock in the lines 132 and 133 to hold valve 126 and drive link 85 in adjusted position without the necessity of maintaining pressure in line 132. However, if desired, valve 122 may be left in its actuated position while valve 123 is actuated to swing and return the boom.

Shifting valve 123 to the right then swings the upper boom section 32 to the right. In this valve movement, pressure line 130 is connected to line 134 and discharge line 131 is connected to line 135. This introduces pressure through line 136 to the upper end of cylinder 98 to retract latch bar 95 and introduces pressure to the rear end of cylinder 75 to extend piston rod 77 and swing the upper boom section as shown in FIGURE 4. Fluid displaced from the forward end of cylinder 75 liows through lines 137 and 135 to tank line 131. Fluid displaced from the lower end of cylinder 98 flows through line 142 and check valve 124 to line 137.

When it is desired to swing the upper boom section forward from its FIGURE 4 position, valve 122 is not moved and valve 123 is shifted to the left to connect line 135 with pressure line 130 and to connect line 134 with tank line 131. This introduces pressure through line 137 to the forward end of cylinder 75 retracting piston rod 77 to swing the boom. Fluid displaced from the rear end of cylinder 75 discharges to tank through lines 136, 134 and 131. Spring 144 prevents valve 125 from opening under the pressure existing in line 137 while the piston rod 77 is moving but when the movement of the boom is stopped by raised lock bar 96, the pressure builds up to a sutiicient value in line 137 to open valve 125 connecting pressure line 137 with line 142. When this occurs, cylinder 98 raises latch bar 95 to latch the boom in straight forward position. Latch bar 95 then remains raised except when the upper boom section again is caused to swing to the right.

When it is desired to swing the upper boom section to the left, the valve 122 is first shifted to the left, causing relay valve 126 to shift to the right and causing drive link to rotate counterclockwise into engagement with pin 84 as shown in FIGURE 2. Valve 122 may be left in actuated position or it may be returned to center position as shown. Then Valve 123 is shifted to the left to extend piston rod 80 in cylinder 76 and retract latch bar 96.

To return the upper boom section from left swing position, valve 122 is not moved and valve 123 is shifted to the right to retract piston rod 80. The return movement of the upper boom section is stopped in straight forward position by the raised latch bar 95 causing the pressure in line 139 to rise and open valve 141 against the closing force of spring 144. The opening of valve 141 admits fluid pressure to line 143 to raise lock bar 96 and lock the upper boom section against movement.

Thus, the cylinder 75 operates to swing the upper boom section right and return it to center and the cylinder 76 operates to swing the upper boom section 90 left and return it to center. When the boom is centered in straight forward position, both lock bars and 96 are always raised to prevent swing. The two manual valves 122 and 123 are preferably arranged for sequential operation and for individual operation of valve 123 by a single operating lever (not shown) manipulable in different directions in the manner of a gear transmission shift lever.

The hydraulic system for levelling and dumping the bucket is shown in FIGURE 6. The forward ends of cylinders 60 are `connected by a `hydraulic line 161 with the lower end of master cylinder 65 and to one side of a three position manual valve 160. The rear or rod ends of cylinders 6i) are connected by a line 162 with the upper or rod end of master cylinder 65 and to the same side of valve 160. The opposite side of valve 160 is connected with pressure line and discharge line 131.

When valve is in its neutral position as shown, the pressure and discharge lines 130, 131 are disconnected from lines 161 and 162 and the latter merely connect the cylinders 60 as slave cylinders to the master cylinder 65. Assuming the bucket 30 to be in the lower carrying position as shown in full lines in FIGURE 1, it is apparent that levelling means must be provided to prevent the bucket from tipping backward and spilling material as the boom rises. Heretofore in the art, this function has been accomplished by a parallelogram linkage connected with the frame of front body section A but such a mechanical levelling linkage cannot be employed in the present loader because of the swinging movements of the upper boom section on its pivot 45.

In the present loader the levelling function is performed by master cylinder 65. As the boom rises, fluid displaced from the upper end of master cylinder 65 is transferred to the rear ends of slave cylinders 60 so that the bucket pivots forward on its pivotal supports 51 to change the angle of the bucket in relation to its support arms 49 in accordance with the change in inclination assumed by the lower boom section 31. Thus, as the boom rises to its broken line position in FIGURE 1, the bucket remains level and does not spill its contents. Fluid displaced from the forward ends of cylinders 60 returns to the lower end of master cylinder 65 in a closed hydraulic system having no connection with pressure and discharge lines 130 and 131.

The bucket is tilted forward for scooping as shown in broken lines in its lower position in FIGURE 1 or for dumping as shown in its alternate raised position by introducing additional fluid from an outside source into the rear or rod ends of cylinders 60 and withdrawing fluid from the forward ends of these cylinders. This function is accomplished by the valve 161). When this valve is moved upward in FIGURE 6, pressure line 130 is connected with line 162 and discharge line 131 is connected with line 161, causing the bucket to tip forward. Whenever valve 160 is returned to its neutral center position, the bucket is hydraulically locked in adadjusted position. To tip the bucket back to carrying position, valve 60 is shifted downward to connect pressure line 131) with line 161 and to connect discharge line 131 with line 162.

Thus, when valve 160 is closed in center position as shown, the bucket cylinders 160 act merely as slave cylinders for levelling purposes but, when the valve is operated, these cylinders perform the additional function of tipping the bucket for scooping and dumping. These functions are not affected by the swinging of the upper boom section on its pivot 45 whereby the bucket may be dumped to either side as shown in FIGURE 4.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A side dump loader comprising a lower boom section mounted on heel pins for vertical movement, a pivot on the outer end of said lower boom section arranged to become vertical when the boom is raised, an upper boom section mounted on said pivot for lateral swinging movement, a loader bucket on said upper boom section, a pair of levers mounted intermediate their ends on said pivot, means for selectively connecting forward ends of one or the other of said levers to said upper boom section, and cylinder and piston rod means arranged to actuate rearward ends of said levers for swinging said upper boom section right or left.

2. A loader as dened in claim 1, said cylinder and piston rod means comprising a right swing cylinder having a piston r-od connected to one of said levers and a left swing cylinder having a piston rod connecte-d to the other lever.

3. A loader as dened in claim 1, said selective connecting means comprising a drive link on said upper boom section movable into engagement with said levers.

4. A loader as delined in claim 1, including an arm on said upper boom section extending rearwardly behind said pivot, and a pair of retractable lock bars on said lower boom section disposed on opposite sides of said arm when said upper boom section is turned straight forward.

5. A vehicle, a lower boom section pivotally mounted on said vehicle for vertical movement, a pivot on the outer end of said lower boom section arranged to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said last pivot, a left swing cylinder on said lower boom section, a right swing cylinder on said lower boom section, and means selectively operatively connecting one or the other of said cylinders mechanically to said upper boom section and mechanically disconnecting the remaining cylinder from said upper boom section to swing said upper boom section right or left from the direction of said lower boom section.

6. A vehicle, a lower boom section pivotally mounted on said vehicle for vertical movement, a pivot on the outer end of said lower boom section arranged to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said last pivot, a left swing cylinder, a right swing cylinder, means selectively operatively connecting one or the other of said cylinders to said upper boom 8 section to swing said upper boom section right or left from the direction of said lower boom section, said means comprising a notched swing drive link movably mounted on said upper boom section, and means operable by said cylinders engageable with said drive link.

7. A vehicle as defined in claim 6, said last means comprising a scissors linkage having arms connected with pistons in said cylinders, and pins on said arms for engaging the notches in said drive link.

8. A vehicle as deiined in claim 6, inclu-ding pivotal mounting means for said drive link, and means for rotating said drive link into engagement with said engageable means.

9. A vehicle as dened in claim 7, said arms of said scissors linkage being pivotally mounted on said last pivot.

10. A vehicle, a lower boom section pivotally mounted on said vehicle for vertical movement, a pivot on the outer end of said lower boom section arrange-d to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said last pivot, a left swing cylinder, a right swing cylinder, means selectively operatively connecting one or the other of said cylinders to said upper boom section to swing said upper boom section right or left from the direction of said lower boom section, and retractable lock bars arranged to lock said upper boom section in straight forward position relative to said lower boom section.

11. A lower boom section mounted for vertical movement, a pivot on said lower boom section arranged to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said pivot, a left swing cylinder on one of said boom sections, a right swing cylinder on one of said boom sections, a movable drive link arranged to selectively operatively connect one or the other of said cylinders with one of said boom sections and disconnect the remaining cylinder to swing said upper boom section right or left from the direction of said lower boom section, and means to shift said drive link to two different positions to effect said selective connections.

12. A lower boom section mounted for vertical movement, a pivot on said lower boom section arranged to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said pivot, a left swing cylinder extending approximately longitudinally along one of said boom sections, a right swing cylinder extending approximately longitudinally along one of said boom sections, a movable drive link having one position operatively connecting said right swing cylinder with one of said boom sections and disconnecting said left swing cylinder to swing said upper boom section right from the direction of said lower boom section, said drive link having a second position operatively connecting said left swing cylinder with one of said boom sections and disconnecting said right swing cylinder to swing said upper boom section left from the direction of said lower boom section, and means to shift said drive link to said two positions.

13. A lower boom section mounted for vertical movement, a pivot on said lower boom section arranged to assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swinging movement on said pivot, a left swing cylinder and a right swing cylinder on one of said boom sections, and a movable drive link arranged to selectively operatively connect one or the other of said cylinders with the other boom section and disconnect the remaining cylinder to swing said upper boom section right or left from the direction of said lower boom section, and means to shift said drive link to two different positions to effect said selective connections.

9 10 14. A lower boom section mounted for vertical move- References Cited by the Examiner ment, a pivot on said lower boom section arranged to UNITED STATES PATENTS assume a vertical position when the boom section is raised, an upper boom section mounted for lateral swing- 2731162 1/1956 Walstroming movement on said pivot, a pair of levers mounted 5 82,9183 3/1958 Wagnr et al' 214-132 intermediate their ends on said pivot, means for seleclg; lackle 1 214-138 tively connecting one end of one or the other of said ndre et a levers to one of said boom sections, and cylinder and FOREIGN PATENTS piston rod means arranged to actuate the other ends of 1,116,360 1/1956 Frama said levers for swinging said upper boom section right lO or left. HUGO O. SCHULZ, Primary Examiner. 

1. A SIDE DUMP LOADER COMPRISING A LOWER BOOM SECTION MOUNTED ON HEEL PINS FOR VERTICAL MOVEMENT, A PIVOT ON THE OUTER END OF SAID LOWER BOOM SECTION ARRANGED TO BECOME VERTICAL WHEN THE BOOM IS RAISED, AN UPPER BOOM SECTION MOUNTED ON SAID PIVOT FOR LATERAL SWINGING MOVEMENT, A LOADER BUCKET ON SAID UPPER BOOM SECTION A PAIR OF LEVERS MOUNTED INTERMEDIATE THEIR ENDS ON SAID PIVOT, MEANS FOR SELECTIVELY CONECTING FORWARD ENDS OF ONE OF THE OTHER OF SAID LEVERS TO SAID UPPER BOOM SECTION, AND CYLINDER AND PISTON ROD MEANS ARRANGED TO ACTUATE REARWARD ENDS OF SAID LEVERS FOR SWINGING SAID UPPER BOOM SECTION RIGHT OR LEFT. 